Anticoag for VTE Part 2

Question 1

4 DOACs

Answer 1

Dabigatran
Rivaroxaban
Apixaban
Edoxaban

Question 2

Unfractionated heparin

Answer 2

Indirect thrombin inhibitor (uses antithrombin)
IV admin
Less favorable pharmacokinetics
Lots of monitoring
Increased risk of HIT
Less effective maybe
But does not depend on renal excretion
More readily reversible

Question 3

Why can you not use warfarin alone for acute VTE?

Answer 3

It leads to transient hypercoagulability (protein C gets depleted quickly)
Warfarin must be overlapped with LMWH

Question 4

What is the minimum LMWH time? And when can you stop it?

Answer 4

Minimum 5 days

Do not stop until INR is therapeutic

Question 5

Why is it ok to use a DOAC alone for acute VTE?

Answer 5

DOACs have a prompt onset of action
Dabigatran and edoxaban were not studied as monotherapies
Rivaroxaban and apixaban have more intense dosing for acute phase

Question 6

2 mechanisms of drug interactions with DOACs

Answer 6

Transport by P-glycoprotein

Metabolism by CYP450

Question 7

Pros and cons of warfarin

Answer 7

Pros: long clinical experience, easily available lab monitoring, effective/cheap/familiar antidote, no renal excretion, cheap
Cons: delayed on and offset of action, requires frequent monitoring, lots of drug and diet interactions

Question 8

Pros and cons of DOACs

Answer 8

Pros: quick on and offset, no monitoring required, few drug interactions, no dietary interactions
Cons: short clinical experience, no readily available lab monitoring, now/new antidotes, renal excretion, expensive

Question 9

What about anticoags in pregnant patients?

Answer 9

Warfarin is teratogenic
DOACs may be teratogenic
LMWH is the only safe option

Question 10

2 reasons to consider thrombolysis

Answer 10

Alleviate acute symptoms of DVT

Prevent post thrombotic syndrome (not actually effective)

Question 11

Post thrombotic syndrome

Answer 11

Chronic swelling, pain, and skin changes after a DVT

Can be a very big problem

Question 12

Phlegmasia cerulea dolens

Answer 12

Venous limb gangrene due to huge DVT
Veins in the leg are entirely occluded by clot
Pressure increases so much that the arterial blood flow becomes compromised
Would do thrombolysis here

Question 13

3 treatment options for patients with active cancer

Answer 13

LMWH with bridging to warfarin (rarely)
DOAC
Long term LMWH alone

Question 14

Pros and cons to LMWH in cancer patients

Answer 14

Pros: little to no extra blood tests, easy to use with procedures, easy to alter dose if low plts, does not require oral route, no chemo interactions, no dietary interactions
Cons: subcutaneous injection, expensive